Fixed breaking change for checkstyle 8.42

[DominicOram]

Description of work

Fixed the config to work for the latest version of checkstyle (checkstyle/checkstyle#4465)

To test:

• With the latest version of checkstyle run the checkstyle checks and confirm they run

Once this is merged everyone will need to update checkstyle, once merged please put the instructions on dev-changes (https://checkstyle.org/eclipse-cs/index.html#!/)

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Code Review

• Is the code of an acceptable quality?
• Do the changes function as described and is it robust?
• Is there associated PR for the release notes?

Final Steps

• Reviewer has also merged the release notes

[JamesKingWork]

This breaks the build as accessModifiers is not available for the Checkstyle version we use in the build. I'm not quite sure how to fix that, but I can't approve it as is

[DominicOram]

I think we should move the build version forward